The next point pertains to the abolition of the slave trade, and the perpetuity of slavery, in the District of Columbia. This District has an area of about fifty square miles; and Mr. Clay proposes, in consideration of transferring its slave marts to Alexandria, on the Virginia side, or to some convenient place in Montgomery or Prince George’s county, on the Maryland side, to divest Congress forever of its right of “exclusive legislation” over it. Should this plan prevail, the perpetuity of slavery in the District will be defended by more unassailable and impregnable barriers than any other institution in Christendom. The President has a veto upon Congress; but two thirds of both Houses may still pass any law, notwithstanding his dissent. Mr. Clay proposes to give, both to Maryland and to the citizens of the District, a veto on this subject;--an absolute veto, not a qualified one, like that of the President of the United States, but one that will control, not majorities merely, but an absolute unanimity in both branches of Congress. By his plan, therefore, three separate, independent powers are to have a veto upon the abolition of slavery in the District of Columbia. And not only so, but while it will require their _joint_ or _concurrent_ action to abolish the institution, any one of them can preserve it. The laws of the Medes and Persians had no such guaranties for perpetuity as this. Mr. Clay’s last point is really too facetious. So solemn a subject does not permit such long-continued levity, however it may be masked by sobriety of countenance. It is, that Congress shall make more effectual provision for the capture and delivery of fugitive slaves; and, as an equivalent for this, it shall bind itself never to interfere with the inter-state traffic in slaves. We are to catch the slaves of the South, and, as though this were a grateful privilege to us, we are to allow them free commerce in slaves, coastwise or inland. By this means, slaves can be transported to the mouth of the Rio Grande, and some hundreds of miles up that river, towards New Mexico, instead of being driven in coffles across the country. The compromise is, that for every slave we catch, we are to facilitate the passage of a hundred into New Mexico.